Vitaly Petrov's future has yet to be sorted because of an indecisive sponsor, according to his manager.

Rumours have linked Petrov with a drive at Caterham, but no announcement has been forthcoming and the team released its driver schedule for the first test today, with Jarno Trulli in the car on Friday. Oksana Kosachenko told RIA Novosti that the delay had been caused by a sponsor not committing, and admitting it was concerning Petrov.

"Of course, he is not very comfortable because we expected them to move a little bit faster," Kosachenko said. "Without these decisions, we cannot move forward."

Kosachenko also said that Narain Karthikeyan's confirmation at HRT did not mean Petrov would have to settle for a reserve role, and that a race seat was still the target.

"I would say, at the moment I have some other options. I'm concentrating more on looking at those options. If, within the next few days, we don't succeed, we are going to talk to some other series and probably we are going to talk to Pirelli as well. There were no negotiations with Pirelli yet.

"[Petrov's] main task is not negotiating, because he is not presenting there. He doesn't even know whom I am negotiating with yet. His main task is to be fit and prepared at any moment to jump into the car and deliver the result."